DETERMINATION OF SOME POLYPEPTIDES USING THE METHOD OF CAPILLARY ZONE ELECTROPHORESIS

For monitoring the purity of polypeptides with FW approximate to 7000 g/mol, pI approximate to 4, two analytical methods, suitable for everyday laboratory practice were developed and tested with regard to the separation efficiency and reproducibility. The first of them is based on tile sample separation in a capillary with a bonded layer on the inner wall, prepared according to Hjerten and Cobb in phosphate buffer (pH 6,2). Relative standard deviation of eight determinations of the same sample was 2,60 %. More handy seems to be tile application of unmodified capillaries with phosphate buffer spiked with 1,4-diaminobutane (pH 7,2). The relative standard deviation of the main substance peak area (1,69 %) and the application of simple uncoated capillaries predestine this method for analyses of sample series.